Even people who don’t care about football have heard of Tim Tebow. Why? Because his good behavior off the field stands out when it seems like arrests are as common as injuries among professional athletes. But haven’t we heard all our lives that sports build character? If that’s the case, why is someone like Tebow the exception instead of the rule?

Sharon Stoll is the director of the University of Idaho’s Center for Ethical Theory and Honor in Competition and Sport and she has spent 20 years asking athletes of all ages to fill out a questionnaire that measures psychological traits. The result: Sports do help develop positive characteristics like loyalty, self-sacrifice, and a strong work ethic. But scores nosedive in areas like honesty, fairness and personal responsibility. And the longer someone plays a sport competitively, the more morally bankrupt they become.

Stoll believes there are two reasons why: First, most coaches adopt a “win at any cost” philosophy.  One that puts the responsibility of fair play on referees and umpires instead of on the athletes themselves. In other words, “It’s only cheating if you get caught.”

The second reason: Parents, coaches, and teachers offer special treatment to exceptional athletes that includes ignoring bad behavior, on and off the field.

What’s this mean to all the future Hall of Famers who are listening? You have to take responsibility for the type of life you lead. And if you’re a parent, you can’t rely on coaches and teammates to teach your kids right from wrong.